US1970806A - Expansion valve - Google Patents

Description

G. LIDSEEN EXPANS I ON VALVE Aug. 21, 1934.

2 Sheets-Sheet 1 Filed March 25. 1952 Aug. 21, 1934.

2 Sheets-Sheet 2 Filed March 25. 1932 ure 5. I g Figure 7 is an enlarged sectional'view taken Patented Aug. 21, 1934 evosos' EXPANSION VALVE Gustave Lidseen; Chicago, Ill. Application. March 25, 1932, Serial No. 601,084

4 Claims.

an expansion 'v-alve of the bellows type with a mounting for the bellows ofsuch character as to effectively seal the valve structure against leakage.

A further object of the invention is to provide in an expansion valve along with bellows,

springs, and adjusting means for the springs of means forsealing the valve against leakage of noxious gases.

A still further object of the invention is to 7'7 improve construction of expansion valves to prevent lealiage and to prevent unauthorized adjustment or tampering.

The above, other, andfurtherobjects of the invention will be apparent from the following description, accompanying drawings, and appended claims.

Embodiments of the present invention are illustrated in 'the accompanying drawings and the views thereof are as follows:

Figure 1 is a verticalsectional view through an expansion valve constructed in accordance with the principles of the present invention and showing one form of toggle means for actuating the needle valve. Inlet open.

Figure 2 is a sectional view taken substantially in the plane of line II-II of Figure 1.

Figure 3 is a sectional view taken substantiallyin the: plane of line IIIIII of Figure 1.

Figure 4. is a'diagrammatic sketch illustrating the toggle movement utilized in actuating the needle valve in accordance with principles or the present invention.

Figure 5 is a vertical sectionalview through an expansion valve showing a modification of the means for actuating the needle valve, with toggle action. Inlet closed.

Figure 6 is an enlarged sectional view taken substantially in the plane of line VI-VI of Figsubstantially in the plane of line VII-VII of Figure 5. 1

Figure 8 is an enlarged sectional view taken substantially in the plane of line VIII-VIII of Figure 5. I

The drawings will now be explained.

The valve structure in Figure *1 comprises a casing or body A having a chamber 13 therein which is illustrated as being'vertically arranged within the casing. An inlet compartment- C is formed in the casing and contains a strainer 1 which overlies the inlet pipe 2 which is secured within the casing A by threaded engagement of a nipple 3 with the walls of the compartment C; A nipple 4 extends below the nipple 3 for receiving a connection from the source of fluid supply.

In the wall of the casing A separating the com partment C from the chamber 13 is a horizontally disposed opening 5 having a counter bore 6 at the-end adjacent the chamber B. A bushing '7 having an opening 8 therethrough preferably of less size than the aperture 5 forms a restricted passage between the inlet compartmentC and the chamber B. The bushing? is retained within the counter bore 6 by peening over the flange or margin 9 about the counter bore portion for se-; curing the bushing inposition. The outer face of the bushing adjacent thepassage 8-is enlarged or conical shaped at'lO to provide a valve seat.

The casingA, opposite the aperture 5, is formed with an enlarged threadedopening 11 which is normally closed by a threaded nipple 12; which nipple has a hollow or counter bored interior 13. A gasket 14 is interposed between theboss forming the opening 11 and a shoulder formedon the nipple or nut 12 to seal the jointtherebetween when the nipple is" screwed home. I Above the inlet compartment 0 is an outlet compartment D with which communicates a threaded ope'ning'15' for receiving an outlet con-' nection. A communicating passage lS extends between the outlet compartment Dand the chamber B of the casing A; The passage 16 is, in Figue 1, shown as inclined downwardly although this inclination or disposition of this" communicating passage may be made as desiredwith reference to the inclination thereof as long asit is disposed above the communicating passage between the inlet compartment C and the chamber B.

The casing A is provided with a threaded por-' tion or part 17 formed with an undercut shoulder 18 for receiving in threaded engagement therewitha threaded apertured nut or plug 19. The plug 19 has a threaded interior for a purpose to be later ex'plainedfv i i r i clip 30.

A bellows 20 is soldered or otherwise securely fastened to a flange 21 formed about the inner lower end of the nut or plug 19. The bellows is closed at its other end which end has brazed or otherwise fastened to it on the outside thereof a seat member 22. Within the bellows a disc 23 is suitably fastened.

A counter bored adjusting nut 24 is threaded in the. interior threaded portion of the plug 19 and has a skirt extending normally below the lower end of the plug 19 when the parts are assembled in operative position in the casing A. Within the skirt of the counter bored member 24 a spring 25 is interposed which bears against the disc 23 on the inner face of the end of the bellows 26. The spring 25 acts to move the closed end of the bellows downwardly as viewed in Figure 1, i. e. elongate the bellows. The spring 25 is tensioned by means of a screw driver or other tool engaging the notch 26 formed in the member 24. In order to prevent unauthorized adjustment of the spring 25 and the bellows 20 and also to prevent unauthorized tampering with the expansion valve in its adjustment, a sealing member or plug 27 is threaded into the interior of the apertured nut 19, after the member 24 has been turned to properly adjust the action of the spring 25 within the bellows 20. The plug 27 is provided with a cylindrical or circular head so as not to be engageable by an ordinary wrench but requires a special tool for turning it. The ordinary attendant would not be provided with such tool and therefore could not surreptitiously interfere with the adjustment of the valve as he could not readily remove the plug. 7 v

The lower portion of the chamber B has cast in it a shoulder 28 which has an aperture 29 passing through it. A clip 30 which is substantially circular in elevation, as may be observed from Figure 2, is provided with a-tailor extension 31 which is inserted through the slot 29 in the shoulder 28. The clip 30 thus is loosely supported in the shoulder. The clip 30 has its central portion depressed to provide a socket 32 for receiving on its concave side the rounded head 33 of the needle valve member 34. Immediately beyond the head 33 the valve member is formed with an annular depression 35 which rests in separated ears 36 formed as part of a key 3'7 fastened to the Thus the needle valve member 34 is loosely mounted in the clip 30 and has ball and socket connection therewith so as to allow play of the valve member. The pointed end of the needle valve member rests at alltimes within the conical portion 10 of the bushing '7 thus being self-guided in its opening and closing movements.

The construction of the needle valve member and the mounting of the same in the manner described provides nothing to draw the needle valve out of alignment with its seat as the valve is actuated in service.

Between the inlet and outlet openings within the chamber B, is a movable member influenced by the action of the bellows20 and the spring 25 to move the needle valve member 34 in passage closing direction responsive to pressure conditions in the outlet connections.

The member illustrated in Figure 1 consists of a dish shaped flap 36 having a tail 3'? loosely enigagedin a recess38 in the valve casing. The

flap 36 is arranged with its convex side upwardly and is provided on its lower or concave face with a shoulder formed by a projection 39 formed as; apartof the flap; There is an opening 40 through the flap as fluid bypass opening.

Within the bored nut or nipple 12 is a spring 41 which normally engages the clip 30 to urge the clip and its supported needle valve member 34 in a direction to close the passage between the inlet compartment and the chamber B.

A link 42 has a reduced end 43 engaging an opening 44 in the clip 30 and at its other end is provided with a reduced neck 45 providing shoulders 46 for engaging the shoulder 39 formed on the under side of the member 36. There is loose connection between the link 42 and the clip 30 and also between the link 42 and the flap 36. The flap and the link act with toggle action to enable movement of the needle valve member 34 in a direction to close the passage between the inlet compartment C and the chamber B whenever the pressure conditions in the outlet connections are such as to set up a vacuum sufiicient to raise the flap 36 against the action of the bellows 20 and the spring 25. Such movement upwardly of the flap 36enables the spring 41 to function to move the needle valve member 34 in a direction to close passage to the chamber from the inlet.

The spring 25 is adjusted to balance the spring 41 so that normally the needle valve member 34 is in fully opened position which it is as illustrated in Figure 1. Consequently any suction created in the outlet will reduce the pressure in the chamber 13 above the flap 36 and allow spring 25 to elongate the bellows thereby moving the valve member 34 in a direction to open communication with the fluid supply and admit more fluid. As the pressure within the chamber builds up, by reason of the admission of fluid, the pressure acts against the bellows to shorten the same against the action of the spring 25 and raises the flap 36.

This action will tend to restrict flow from the.

inlet. The spring 25 is so adjusted that when the suction reaches a predetermined point the spring will become efiective to move the bellows and the disc 22 downwardly thus returning the flap 36 to normal position and thus opening the needle valve to admit more fluid under pressure to the chamberB then to the outlet D through the passage 16.

The mounting of the needle valve member 34 loosely on the clip 30 enables operation of the needle valve without possibility of it being drawn out of alignment with its seat as the point at all times engages the seat irrespective of the position of the point with respect to the closing of the passageway through the bushing.

The modification illustrated in Figure 5 contains many of the same elements as identified and described with reference to Figure 1 and accordingly such elements will, in Figure 5, be identified and referred to by the same reference characters.

The valve structureof Figure 5 has an apertured plug50 which is quite similar to the plug 19 of the valve structure of Figure 1. The bellows 20 are secured to the plug 50 by being soldered or otherwise fastened to a flange 51 on the'lower end of the plug. The aperture of the plug is threaded to receive a threaded adjusting the plug 59 by means of a screw driver engaging the slot 54 in such plug. The plug 52 it will be noted is not provided with the depending skirt of the plug 24 of the form of Figure 1 instead the apertured plug 50 serves the purpose of the skirt. The threaded aperture of the plug 50 is closed by means of the sealing plug 27 in the same man-- her and for the same purpose as described with reference. to. the valve structure of Figurel.

' In the valve structure of Figure. 5. the outlet passage 16. between the chamber B and the out let compartment SD is. perpendicular to. the axis of the chamber B.

' The valve casing A of the structure of Eigure 5 has its lower end extended to. lengthen the chamber B for the reception of an elongated movable member or rider within said compartment which is responsiveto' pressure conditions in the outlet fQnactuating theneedle valve 34 to control passage. from the inlet.

' The rider or movable member of the valve structure of Figure 5 comprises a flat topv portion from which depend two spacedlegs 5.6 and 5'1. The outer'surfaces of these legsv are arcuate to conform to the cylindrical section of the lower portion of the chamber B. The legs 56- and 57 carry rollers 58 and 59 for engaging the chamber wall to prevent. canting of the member as it is vertically moved within said chamber.

A roller 60 is carried on a stub shaft 61 formed in the end of a screw' 62 which roller 60 lies between the legs 56 and 57 thus preventing canting of the'movable member in a directionat right angles to that governed by the rollers 58 and 59.

A spring 63 is interposed between the bottom of the chamber B and the lower end of the member 55 to balance the weight of this member. in order that the same maybe readily responsive to pressure variations or conditions in. the outlet.

The screw 62' is adjustable from outwardly of the casing as the head 64 is provided with a slot 65 to receive a screw driver tofproperlyposition.

the roller 60 for guiding purposes. The legs 56 and ST'are provided with notche 65 engaging the shoulder's46 of'the. link 42. The

link 42 of the structure'of. Figure 5 cooperates with the clip 30 in the same manner as the link 42.

of the structure of Figure 1 it being loosely assoc'iated' with the clip and the legs.

T The arrangement of parts in Figure 5: appears with the needle valve closedagainst its seat to stop passage from the inlet compartment C. to the chamber B a'condition which arises when there is too much pressure in the chamber.

As the instrumentality, such for instance as a compressor, attached to the outlet connections, operates to reduce the pressure in the outlet, such reduction of pressure creating suction within the upper part of the chamber B and reduces pressure against the bellows 20, thereupon allowing the spring 25 to become efifective to move the member 55 downwardly and thus, through the link 42 and the clip 30, open the needle valve 34 admitting more fluid under pressure to the interior of the chamber B. As this pressure builds up the bellows 20 contracts or shortens and the tendency of the spring 41 to close the needle valve 34 through toggle connections with the member 55 raises such member to maintain the same in balance depending on the pressure conditions in the outlet connections.

The present valve is very useful in refrigerator installation between the condenser and the compressor. The outlet is connected to the compressor thereby resulting in decreased pressure in .the part of chamber B or 13 above the flap 36 or rider 55. Such reduced pressure thus tends to result in a reduction in the length of the bellows, or, in other words, a shortening of the bellows. The spring within the bellows, however, tends to oppose such shortening thus striving to mainjoints making leaktight joints to prevent escape of noxious and dangerous gases, such as are sometimes used for refrigerants. 1

The needle valve is. self-seating, thus eliminating. accurate machine fit of needle guides and seats. Ihe valve always finds its own seat as the. point is never removed from the conical opening 10 in the bushing I. The loose connection between the clip 30 and the needle valve member 34 allows bodily movement of the needle in its seating movements; thereby assuring. a tight closure of the passage when. the needle is moved to close the passage.

The toggle action of the flap, link and clip makes possible easy manufacture and assembly and operation of these parts as well as positive actuation of the needle valve. The outlet may be anywhere in the casing A or A as long as it. is above the inlet.

The arrangement and installation of the bellows j and apertured plug make possible leak tight connection therebetween and the plugs 2 seal such parts against escape of gas.

The plugs 19, 19a and 12 have the outer sur faces cylindrical, with a notch 6'7 in a cylindrical surface for engagement by a pin in the special wrench used for applying and removing these plugs. The oasingsA and A may besand castings or die'castings.

. The invention has been described more or less precisely herein, yet it is to be understood that the invention is not to be limited thereby, as. changes may be made in the arrangement and proportion of parts, and'equivalents. may be sub-.

stituted, without departing from the spirit and scope of the invention.

The invention is claimed as follows:

1. An expansion valve structure including a valve body having a chamber in it with inlet and outlet connections, said body having a restricted passage between said inlet and chamber with a conical end opening into said chamber, a pointed self-seating needle valve arranged for controlling fluid passage through said inlet and into said chamber, said valve being arranged with itspoint at all times within said conical opening, a clip rockably carried and supported by said body and loosely engaging and supporting the opposite end of said needle valve, a spring coaxially arranged with respect to the needle valve axis and bearing against said clip and tending to move said valve in closing direction, a second spring disposed in right angular relationship with respect to said first spring, a member interposed in said chamber between said inlet and outlet adapted to move in direction substantially perpendicular to the movement of the needle valve and positioned in the path of fluid flow from the inlet to the outlet, a link extending between said member and said clip, said link and said member constituting toggle means interposed between said second spring and said clip, said second spring being normally efiective' through said toggle means for maintaining said clip pressed against said first spring in a manner to normally maintain said valve in open position, and means within said chamber responsive to pressure conditions therein acting against said second spring to shorten it, such shortening of said second spring relieving resistance to said toggle means against said clip to enable said first mentioned spring to move the valve in closing direction.

2. An expansion valve structure including a body having a chamber in it with inlet and outlet connections,'a pointed needle valve for controlling fluid admission through said inlet, a conical seat at the'discharge end of said inlet for receiving the point of said needle valve, a floating support for the other end of said needle valve comprising a clip rockably mounted in said body and loosely engaging said needle valve, a spring acting against saidclip to normally urge said needle valve against said seat, an inflexible flap rockably mounted in the body and having a shoulder, a link between said clip and said flap shoulder, said link and flap constituting toggle means, a second spring acting against said flap to normally urge said toggle means in a direction to unseat said needle valve against the action of said first mentioned spring, the construction'of said springs being such that in the absence of pressure at the 'inlet said second spring overbalances the tendency of said first spring to close said needle valve against the seat, and means subject to pressure conditions in said chamber efiective to overcome the pre-z ponderance of said second spring and enable said first spring to move said needle valve in" closing direction. 1

3. A valve structure including a body providing a chamber and inlet and outlet communications with said chamber, a valve member for controlling fluid admission through the inlet to the chamber, means to seat said valve member, means to unseat'said valve member, said latter means including an inflexible flap rockably supported within said chamber in the path of fluid flow from the inlet to the outlet disposed crosswise of the path of fluid travel so as'to be subjected to movement in one direction by the fluid flow and occupying substantially all of the crosssectional area of the fluid path adjacent said flap, a link connecting said'flap and said first means, said link and flap constituting toggle means, a spring acting against said flap tending normally to move it in a direction to spread said toggle means to unseat said valve member, and means responsive to pressure conditions in said chamber for causing movement of said flap in opposition to said spring to enable said valve seating means to seat said valve.

4. An expansion valve structure including a valve body having a chamber in it with inlet and outlet connections, said inlet having a conical seat adjacent its opening into said chambena pointed self-seating needle valve arranged for controlling fluid passage through said inlet and into said chamber, said valve being arranged with its point at all times within said conical opening, a clip rockably carried and supported by said body and loosely engaging and supporting the opposite end of said needle valve, a spring bearing against said clip tending to move said valve in closing direction, aninflexible member in said chamber between said inlet and said outlet adapted to'be moved in one direction by said fluid flow and positioned in the path of fluid flow from the inlet to the outlet, a second spring acting against said member for moving it in the opposite direction, linkage extending between said member and said clip, said linkage and said member constituting toggle means interposed between said second spring and said cli said second spring being normally efiective through .1

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